1. Technical Field
The present invention relates generally to processing gray scale images, and more specifically relates to a gray scale image cleaning system and method for improved check code line optical character recognition (OCR).
2. Related Art
With the passage of the Check 21 Act in 2004, the bank of first deposit is now allowed to send an electronic image, in lieu of an actual item (e.g., a paper check), for collection. In order to process the electronic image, the paying bank must be able read the code line via an optical character recognition (OCR) engine, since no magnetic ink is present to utilize a traditional magnetic ink character recognition (MICR) engine. Thus, there is accelerated interest in the ability to perform OCR on the code line of a check image.
While ANSI (American Numerical Standards Institute) specifications call for a clean code line region, the code line region is often polluted by check print background, signature descenders and other forms of video noise. While these foreign writings do not affect MICR readability, they offer serious challenges to the OCR engines. For instance, as can be seen in FIG. 2, an entry in the memo field of a sample check includes a “descender” that crosses into, and pollutes the code line. This interference may cause the OCR engine to fail or deliver erroneous “read” information, which in turn results in laborious manual operations and costs.
The cited problem becomes worse as the video contrast between useful foreground information (i.e., MICR Characters) and video noise increases. Thus, the ability to produce black white images free of video noise becomes increasingly difficult. Accordingly, a need exists for a system that can effectively clean up the pollution found in check code lines.